In recording/reproducing apparatus such as a cassette tape recorder etc. a run count of tape is displayed by a conventional, mechanical tape counter. Recently, an electron-optical display device has been contemplated or put to practice in which various data such as tape run data or time count data are simultaneously or selectively displayed. Where, in addition to tape run data, various data are to be displayed on the display section, it is necessary to simultaneously effect, in addition to the tape run counting, a time count operation for obtaining time count data on an operation for judging count contents (count zero) for stopping a motor at a beforehand preset tape run value. Suppose that these operations are performed by a sequential controller based on, for example, a microprogram. If in this case the tape is run at fast speed, a fast-speed count pulse is outputted, thereby affecting the other control function. This will lead to a miscount. If, for example, the time count process is set higher in priority level than the tape run count process, the tape run count process is not accepted during the time count process, since it is lower in priority level than the time count process. There is, therefore, a risk that pulses to be counted will be omitted. A longer pulse generating cycle is required not to generate tape run pulses during the time count process. If during the above-mentioned longer pulse generating cycle a tape run is displayed on the electronic count display device, a little irritation is accompanied due to such longer time interval, causing some inconvenience.
FIG. 1 shows a time chart of the conventional apparatus. A pulse output cycle shown in FIG. 1A bears a one-to-one correspondence with respect to the rotation cycle of a pinch roller or a reel shaft. When the pulse is generated, a time count section in the apparatus effects a count operation (FIG. 1B), count contents judging operations (FIG. 1C) etc. in synchronism with a rise of the above-mentioned pulse. Now suppose that the other operation such as a time count operation is effected. If in this case the pulse (FIG. 1A) is superposed with respect to the pulse of the time count process (see FIG. 1D), the time count section in the apparatus can not detect a new input pulse and it merely judges an input as shown in FIG. 1E. It will be understood upon comparison between the input (FIG. 1A) and the count pulse (FIG. 1E) that when a count value is shifted from "12" to "13" a count error occurs provided that the count value is started from "10". In order to prevent such erroneous operation the count function of the tape counter is separated from a circuit system for processing the other data and is operated independently. This method, however, involves an expensive, complicated circuit.